US3940551A - Apparatus and method for the melt reduction of iron oxides - Google Patents

Apparatus and method for the melt reduction of iron oxides Download PDF

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Publication number
US3940551A
US3940551A US05/455,949 US45594974A US3940551A US 3940551 A US3940551 A US 3940551A US 45594974 A US45594974 A US 45594974A US 3940551 A US3940551 A US 3940551A
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United States
Prior art keywords
electrode
arc
iron oxide
feeding
melt
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Expired - Lifetime
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US05/455,949
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English (en)
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Bernt Ling
Bjorn Widell
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ABB Norden Holding AB
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Allmanna Svenska Elektriska AB
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    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B11/00—Making pig-iron other than in blast furnaces
    • C21B11/10—Making pig-iron other than in blast furnaces in electric furnaces
    • C—CHEMISTRY; METALLURGY
    • C21—METALLURGY OF IRON
    • C21B—MANUFACTURE OF IRON OR STEEL
    • C21B13/00—Making spongy iron or liquid steel, by direct processes
    • C21B13/12—Making spongy iron or liquid steel, by direct processes in electric furnaces
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P10/00—Technologies related to metal processing
    • Y02P10/10—Reduction of greenhouse gas [GHG] emissions
    • Y02P10/134—Reduction of greenhouse gas [GHG] emissions by avoiding CO2, e.g. using hydrogen

Definitions

  • the iron oxide material in powder or granular form is continuously fed to a molten carbonaceous iron bath where the carbon reacts with the oxygen to form the crude iron bath which is tapped continuously or as required from the hearth containing the bath.
  • the first stage comprising a prereduction effected by heating the iron oxide material while in a reducing gas
  • this first stage only partially reducing the iron oxide content of the material involved.
  • the gangue results in a slag floating on the molten bath, and the latter may also support a layer of carbonaceous material such as coke particles. Such layers floating on the bath prevent direct contact with the latter by the iron oxide material, preventing a rapid reduction of the iron oxide.
  • the hearth containing the carbonaceous bath is ordinarily enclosed so that the gas resulting from the reaction of the iron oxide with the carbon can be carried away via an exhaust arrangement. Therefore, if the powdered material is floating around within the enclosed hearth, an undesirably large amount may be drawn off by the exhaust instead of contacting the bath.
  • the object of the present invention is to eliminate the above disadvantages, or at least, substantially reduce the problems they cause.
  • the electrode is normally made the cathode and the carbonaceous bath is made the anode, the bath being contained by a suitable conductive hearth.
  • the current is, of course, a direct current and has adequate power and a suitable voltage for forming the arc.
  • a tubular electrode is used, the arc between it and the molten carbonaceous bath causing a meniscus to be formed where the arc is drawn via the bath.
  • This meniscus is an upward bulge formed in the iron bath which rises high enough so the carbonaceous material floating on the bath, and slag if it is present, gravitationally flow from the crown of the meniscus leaving this crown exposed as naked metal.
  • the tubular electrode contains a refractory tube having a smaller outside diameter than the inside diameter of the tubular electrode, thus forming an annular passage exending through the electrode together with the passage formed by the inside of the refractory tube.
  • the iron oxide particles which may be in the form of partially or prereduced iron ore, is fed via the refractory pipe to the arc, while at the same time a non-oxidizing gas is fed through the annular passageway so as to circumferentially surround the falling stream of iron oxide material.
  • the latter is confined by the annular gas stream until it contacts the naked metal at the crown of the meniscus.
  • This annular flow of gas is ejected under pressure and confines the powdered particles to prevent them from adhering to the arcing tip of the tubular electrode.
  • the magnetic and electric forces of the arc have the effect of further confining the flow of powdered particles.
  • the combined effects of the annular gas stream and of these magnetic and electric forces are such that practically all, if not all, of the powdered particles of the iron oxide material, impinge on the naked iron bath exposed by the meniscus.
  • FIG. 1 is a vertical section showing the enclosed hearth, the electrode assembly, and the feeding of the particulated iron oxide material
  • FIG. 2 is a vertical section on a greatly enlarged scale relative to FIG. 1 and showing the action involved.
  • FIG. 1 the tubular electrode 11 is shown operating as a cathode and powered by direct current, the anode connection to the bath being shown at 12.
  • the electrode 11 may be made of any of the usual graphite materials.
  • the fully enclosed hearth is shown at 13 and here again, the construction may be in accord with electric furnace practice in general.
  • the annular passage is shown at 14 as being fed with non-oxidizing gas at A--A, this annular passage being formed by the refractory feeding tube 15 for the powdered iron oxide material, such as the partially reduced ore, assuming the two-stage reduction practice is used.
  • This tube 15 as shown by FIG. 2, terminates a short distance above the bottom or arcing end of the electrode 11, to prevent the tube 15 from being excessively heated by the arc.
  • the tube 15 is, of course, electrically non-conductive, it preferably being made of ceramic material.
  • the gas fed at A--A may be argon, nitrogen, helium, carbon monoxide, hydrogen, etc. It should be a non-oxidizing gas relative to the iron oxide material.
  • the tube 15 is fed via a batching vessel or chamber 16 via a supply tube 17 under the control of the valve 18 which permits adjustment of the flow rate.
  • the batching vessel 16 is maintained only partially full so that a gas space exists above the material, this preventing pulsations or other irregularities in the supply of the powdered material to the bath in the hearth.
  • FIG. 2 the molten crude iron bath is shown at 19 with the carbonaceous material 20 floating on the bath.
  • This carbonaceous material may be coke having a particle size of between 3 and 8 mm supplied directly to the hearth 13 or through the tube 15 either in batches or mixed with the powdered iron oxide material.
  • the enclosed hearth or furnace contains an atmosphere of carbon monoxide and possibly hydrogen, and of the inert gas, and this is drawn off through the gas exhaust port 21, shown in FIG. 1, preferably in such a manner as to keep the atmosphere within the enclosed furnace slightly below atmospheric pressure, assuring that all of the gases can be drawn off via the exhaust port 21 and not elsewhere.
  • the molten metal bath level may be maintained preferably by continuously withdrawing the crude iron from a tapping hole indicated at 22. It is to be understood that the anode connection 12, powered by the line 23, must carry current to the molten bath, this being done by making the bottom of the furnace, shown at 24, of electrically conductive material, such as graphite.
  • the arcing distance between the bottom end of the cathode electrode and the top level of the molten bath 19 should, of course, be kept relatively at a constant value. This may be done by controlling the rate by which the molten bath is tapped at 22.
  • FIG. 2 shows the action obtained by the practice of this invention.
  • the meniscus which is formed by the action of the currents, is shown at 25, the carbonaceous material 20 being floated downhill to an extent exposing a crown 26 of naked metal.
  • the flow of powdered iron oxide material is shown at 15a and it will be noted that here this flow impinges on the crown 26, the latter being indented somewhat, thus indicating the very effective contact obtained between the powdered material and the naked crown of the meniscus 25.
  • the distance h indicates the arcing distance and as can be seen here, as is illustrated only on the right-hand side of FIG. 2, the arc 11a is drawn inward to form an annular converging space 27 containing the annular jet of the non-oxidizing gas under pressure.
  • the powdered stream 15a may also contain powdered fluxing materials, but any slag layer, as indicated at 28, is gravitationally kept free from the active reaction zone at the crown 26.
  • the electrode 11 gradually burns away, requiring successive attachments of new electrodes to its upper ends as by the usual threaded arrangement.
  • the tube 15 To make the connection, the tube 15 must be withdrawn, putting the desired continuous operation in a shut-down condition for the time required to make the connection and handle the various parts.
  • completely continuous operations may be obtained by making the electrode 11 as a longitudinally split electrode (not shown), this avoiding the need for any handling of the tube 15 and its associated parts, while one section of electrode is used after another.
  • the distance h should be kept at a constant value as is common in electric furnace practices.
  • This may be done by continuously lowering the electrode 11 as required to maintain this distance, or the reduction operation may start out with a very shallow bath layer in the furnace 13, which level, by judicious tapping at 22, is permitted to rise as required to keep the distance h at the desired value.
  • the tubular electrode forms an arc of rather extensive cross-sectional area.
  • the gas pressure of the gas introduced at A--A should be high enough to form a strong confining sheath in the area 27, holding the stream of powdered iron oxide material together until it impinges on the crown 26 of the meniscus 25, the desired force of this impingement being indicated in FIG. 2 by the fact that this crown is shown as slightly depressed by the force of the stream of powdered metal oxide.
  • this stream may include the powdered coke or other carbonaceous material.
  • the electrode has been described as being made of graphite, it may be formed with an electron emitting zone comprising, for example, thorium, barium or substances with similar properties, thus obtaining a spot or zone for electron emission.
  • the arc In addition to a high deoxidation or reduction rate obtained by the formation of the arc on the naked metal of the crown 26 of the meniscus 25, the arc operates in a relatively quiet manner. Because of the annular gas jet and possibly a confining effect due to the annular arc, practically all of the powdered iron oxide material and any powdered carbonaceous material added with it, is confined directly to the bath where, as just indicated, the reaction rate is very rapid, this avoiding the problem of excessive dust floating around above the molten bath within the furnace enclosure.
  • a feeding rate of the powdered metal oxide material can be in the area of 30 tons of powder per hour.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Manufacturing & Machinery (AREA)
  • Materials Engineering (AREA)
  • Metallurgy (AREA)
  • Organic Chemistry (AREA)
  • Vertical, Hearth, Or Arc Furnaces (AREA)
  • Manufacture Of Iron (AREA)
  • Refinement Of Pig-Iron, Manufacture Of Cast Iron, And Steel Manufacture Other Than In Revolving Furnaces (AREA)
  • Manufacture And Refinement Of Metals (AREA)
US05/455,949 1973-03-30 1974-03-28 Apparatus and method for the melt reduction of iron oxides Expired - Lifetime US3940551A (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
SW7304515 1973-03-30
SE7304515A SE371651C (sv) 1973-03-30 1973-03-30 Sett och anordning for smeltreduktion

Publications (1)

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US3940551A true US3940551A (en) 1976-02-24

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JP (1) JPS5438966B2 (enrdf_load_html_response)
CH (1) CH598352A5 (enrdf_load_html_response)
DE (1) DE2412887C3 (enrdf_load_html_response)
FR (1) FR2223459B1 (enrdf_load_html_response)
GB (1) GB1455221A (enrdf_load_html_response)
SE (1) SE371651C (enrdf_load_html_response)

Cited By (17)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4079185A (en) * 1975-04-02 1978-03-14 Asea Aktiebolag Method and apparatus for the melt reduction of iron oxides
US4080511A (en) * 1975-04-02 1978-03-21 Asea Aktiebolag Apparatus for the melt reduction of fine-grained iron oxide material
US4122293A (en) * 1977-04-19 1978-10-24 Georgy Mikhailovich Grigorenko Feed system for plasma-arc furnace
US4146390A (en) * 1975-06-19 1979-03-27 Asea Aktiebolag Furnace and method for the melt reduction of iron oxide
US4152532A (en) * 1976-12-29 1979-05-01 Daidotokushuko Kabushikikaisha Means and method of heating
US4177061A (en) * 1977-06-09 1979-12-04 Asea Aktiebolag Method for making iron-chromium alloys
US4394163A (en) * 1980-06-23 1983-07-19 Asea Ab Process for the manufacture of crude iron and synthesis gas
US4754463A (en) * 1986-02-19 1988-06-28 Asea Ab Hollow arc electrode
US5711017A (en) * 1995-09-19 1998-01-20 Exide Corporation Process for the destruction of chemical agents and munitions
US5942023A (en) * 1997-02-12 1999-08-24 Exide Corporation Process for recovering metals from electric arc furnace (EAF) dust
EP1119734B1 (fr) * 1998-10-06 2002-05-08 Paul Wurth S.A. Procede pour l'enfournement de fines ou de granules dans un four a arc
US6391081B1 (en) * 1999-03-25 2002-05-21 Sony Corporation Metal purification method and metal refinement method
US20040060389A1 (en) * 2001-02-23 2004-04-01 Jean-Luc Roth Method for producing a melt iron in an electric furnace
US20050274224A1 (en) * 2004-06-12 2005-12-15 Leonard Reiffel Method and apparatus for carrying out a metallurgical process
WO2019096808A1 (de) * 2017-11-20 2019-05-23 Sms Group Gmbh Verfahren zur herstellung einer metallischen schmelze in einem ofen
RU2756057C2 (ru) * 2020-02-26 2021-09-24 Федеральное государственное автономное образовательное учреждение высшего образования "Уральский федеральный университет имени первого Президента России Б.Н. Ельцина" Способ получения ванадиевого чугуна из железованадиевого сырья
CN114040997A (zh) * 2019-06-21 2022-02-11 三菱重工业株式会社 电解冶炼炉

Families Citing this family (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
AT376702B (de) * 1983-04-06 1984-12-27 Voest Alpine Ag Verfahren zum betrieb einer metallurgischen anlage
NO157876C (no) * 1985-09-23 1988-06-01 Sintef Fremgangsmaate og apparat for gjennomfoering av varmebehandling.
FR2611876B1 (fr) * 1987-03-04 1989-08-04 Clecim Sa Four electrique a courant continu
AT402939B (de) * 1992-07-16 1997-09-25 Voest Alpine Ind Anlagen Verfahren und anlage zum herstellen einer metallschmelze
RU2296165C2 (ru) * 2005-05-04 2007-03-27 Ооо "Твинн" Способ прямого восстановления металлов из дисперсного рудного сырья и устройство для его осуществления
RU2296166C2 (ru) * 2005-05-13 2007-03-27 Анатолий Владимирович Николаев Способ прямого восстановления металлов из дисперсного рудного сырья и устройство для его осуществления
RU2355775C2 (ru) * 2007-02-16 2009-05-20 Ооо "Твинн" Способ прямого восстановления металлов
RU2352643C1 (ru) * 2007-07-12 2009-04-20 Институт металлургии и материаловедения им. А.А. Байкова РАН Способ восстановления металлов группы железа природным газом и устройство для его осуществления
RU2612330C2 (ru) * 2014-12-30 2017-03-07 Открытое акционерное общество "Научно-исследовательский институт металлургической теплотехники" (ОАО "ВНИИМТ") Способ прямого восстановления материалов, содержащих оксиды металлов, с получением расплава металла и устройство для осуществления способа
JP7373361B2 (ja) * 2019-11-07 2023-11-02 三菱重工業株式会社 電解製錬炉及び電解製錬方法
RU2757772C2 (ru) * 2020-01-27 2021-10-21 Адель Талгатович Мулюков Способ прямого извлечения металлов из оксидных форм металлосодержащего сырья, различных видов руд, техногенных отходов и устройство для прямого извлечения металлов из различных форм в металлическую или другие оксидные фазы

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3004137A (en) * 1960-06-07 1961-10-10 Comb And Explosives Res Inc Method and apparatus for the production of high gas temperatures
US3101385A (en) * 1960-04-11 1963-08-20 Northwestern Steel & Wire Co Method and means for electric melting
US3105864A (en) * 1960-01-20 1963-10-01 Northwestern Steel & Wire Co Means of increasing arc power and efficiency of heat transfer
US3432606A (en) * 1967-03-07 1969-03-11 Exxon Research Engineering Co Stabilized arcs in electric furnaces
US3723630A (en) * 1971-06-28 1973-03-27 B Paton Method for the plasma-ac remelting of a consumable metal bar in a controlled atmosphere
US3789127A (en) * 1972-01-18 1974-01-29 British Steel Corp Arc furnaces

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3105864A (en) * 1960-01-20 1963-10-01 Northwestern Steel & Wire Co Means of increasing arc power and efficiency of heat transfer
US3101385A (en) * 1960-04-11 1963-08-20 Northwestern Steel & Wire Co Method and means for electric melting
US3004137A (en) * 1960-06-07 1961-10-10 Comb And Explosives Res Inc Method and apparatus for the production of high gas temperatures
US3432606A (en) * 1967-03-07 1969-03-11 Exxon Research Engineering Co Stabilized arcs in electric furnaces
US3723630A (en) * 1971-06-28 1973-03-27 B Paton Method for the plasma-ac remelting of a consumable metal bar in a controlled atmosphere
US3789127A (en) * 1972-01-18 1974-01-29 British Steel Corp Arc furnaces

Cited By (20)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4079185A (en) * 1975-04-02 1978-03-14 Asea Aktiebolag Method and apparatus for the melt reduction of iron oxides
US4080511A (en) * 1975-04-02 1978-03-21 Asea Aktiebolag Apparatus for the melt reduction of fine-grained iron oxide material
US4146390A (en) * 1975-06-19 1979-03-27 Asea Aktiebolag Furnace and method for the melt reduction of iron oxide
US4152532A (en) * 1976-12-29 1979-05-01 Daidotokushuko Kabushikikaisha Means and method of heating
US4122293A (en) * 1977-04-19 1978-10-24 Georgy Mikhailovich Grigorenko Feed system for plasma-arc furnace
US4177061A (en) * 1977-06-09 1979-12-04 Asea Aktiebolag Method for making iron-chromium alloys
US4394163A (en) * 1980-06-23 1983-07-19 Asea Ab Process for the manufacture of crude iron and synthesis gas
US4754463A (en) * 1986-02-19 1988-06-28 Asea Ab Hollow arc electrode
US5711017A (en) * 1995-09-19 1998-01-20 Exide Corporation Process for the destruction of chemical agents and munitions
US5942023A (en) * 1997-02-12 1999-08-24 Exide Corporation Process for recovering metals from electric arc furnace (EAF) dust
EP1119734B1 (fr) * 1998-10-06 2002-05-08 Paul Wurth S.A. Procede pour l'enfournement de fines ou de granules dans un four a arc
US6452955B1 (en) 1998-10-06 2002-09-17 Paul Wurth S.A. Method for feeding fines or granules into a light-arc furnace
US6391081B1 (en) * 1999-03-25 2002-05-21 Sony Corporation Metal purification method and metal refinement method
US20040060389A1 (en) * 2001-02-23 2004-04-01 Jean-Luc Roth Method for producing a melt iron in an electric furnace
US7169205B2 (en) * 2001-02-23 2007-01-30 Paul Wurth S.A. Method for producing a melt iron in an electric furnace
US20050274224A1 (en) * 2004-06-12 2005-12-15 Leonard Reiffel Method and apparatus for carrying out a metallurgical process
US7674315B2 (en) 2004-06-12 2010-03-09 Iron Mount Corporation Method and apparatus for carrying out a metallurgical process
WO2019096808A1 (de) * 2017-11-20 2019-05-23 Sms Group Gmbh Verfahren zur herstellung einer metallischen schmelze in einem ofen
CN114040997A (zh) * 2019-06-21 2022-02-11 三菱重工业株式会社 电解冶炼炉
RU2756057C2 (ru) * 2020-02-26 2021-09-24 Федеральное государственное автономное образовательное учреждение высшего образования "Уральский федеральный университет имени первого Президента России Б.Н. Ельцина" Способ получения ванадиевого чугуна из железованадиевого сырья

Also Published As

Publication number Publication date
DE2412887A1 (de) 1974-10-10
FR2223459A1 (enrdf_load_html_response) 1974-10-25
SE371651B (enrdf_load_html_response) 1974-11-25
DE2412887C3 (de) 1980-03-27
JPS5438966B2 (enrdf_load_html_response) 1979-11-24
FR2223459B1 (enrdf_load_html_response) 1978-03-24
CH598352A5 (enrdf_load_html_response) 1978-04-28
DE2412887B2 (de) 1979-07-26
JPS49123415A (enrdf_load_html_response) 1974-11-26
GB1455221A (en) 1976-11-10
SE371651C (sv) 1976-12-06

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